The harsh winter in America was caused by a rare coincidence of weather events, say scientists

Scientists have shown that a severe snowfall in North America and Northern Europe in the winter of 2009-2010 was caused by a rare, once in a century, collision of two weather systems.

They concluded the harsh winter and heavy snow was an example of hard to predict weather events, not a change in climate.

They analysed historical snow records.

The research was published in Geophysical Research Letters.

In the winter of 2009-2010 much of Northern Europe experienced heavy snow and temperatures were at the lowest they had been for nearly 30 years. At the same time, record snowfall hit Washington DC and other parts of America’s “Mid-Atlantic states”.

Some news reports took the extreme cold weather as evidence against climate change.

By analysing 60 years of snowfall measurements and satellite data, researchers concluded the anomalous weather conditions were caused by an unusual combination of an El Nino event and the rare occurrence of a strongly negative North Atlantic Oscillation (NAO).

El Nino events result from a periodic warming of the tropical Pacific Ocean coupled with changes in the atmosphere. El Ninos move storm systems in the Northern Hemisphere towards the equator. They occur every few years and can be predicted up to a few seasons in advance.

The North Atlantic Oscillation (NAO) is climatic phenomenon resulting from shifts in atmospheric pressure between two regions above the North Atlantic Ocean. Large changes can only be forecast a week or two weeks in advance.

When the NAO enters a strongly negative phase, cold air repeatedly comes down from the Arctic. This affects eastern North America, and Western Europe.

Snow that covered most of the UK was caused by a rare weather system bringing down cold air from the Arctic

Richard Seager, a meteorologist with the Lamont Doherty Earth Observatory at Columbia University, US, is one of the lead authors of the paper.

“The NAO was probably as negative as it’s ever been in the instrumental record, which goes back to the early 1800s. This was a once in a century type of event,” he told BBC News.

It was this combined with the El Nino event that caused the severe snowfall in North America.

“The NAO on its own doesn’t cause much precipitation in America. It just makes it cold. The El Nino makes the US wetter than normal so combined with the NAO it caused the precipitation in America to fall as snow,” he told BBC News.

The researchers also believe it is unlikely this combination will occur in the near future. Data from tree rings have shown that these same conditions caused by the same combination of weather systems happened over 200 years ago in the winter of 1783 – 1784 in Northern Europe and North America.

Many people have concluded the extreme winter in 1783/84 was caused by the eruption of an Icelandic volcano. But the researchers believe it was caused by the same combination of weather events that caused last year’s harsh winter.

Richard Seager also believes the research is a counter to suggestions that the cold winter is evidence against climate change.

“Weather will continue to be weather. You have to average over a lot of weather to get the climate trends. There doesn’t seem to be any need to evoke anything else other than that,” he told BBC News

http://www.bbc.co.uk/news/science-environment-11152077

Evacuations have begun in areas of the US East Coast likely to be hit by Hurricane Earl.

The hurricane has strengthened to a category four storm again, generating sustained winds of 215km/h (135mph).

President Barack Obama said officials needed to be ready for a “worst case” scenario in a call to the US Federal Emergency Management Agency (Fema).

North Carolina’s Governor Beth Perdue has declared a state of emergency.

US officials have ordered a mandatory evacuation for thousands of visitors and residents on Ocracoke Island and Hatteras Island.

Both islands are part of North Carolina’s Outer Banks, a region popular with tourists.

Fema has warned people along much of the the Eastern Seaboard of the US to be vigilant and follow official bulletins.

Forecasters at the National Hurricane Center said they expected the hurricane to turn north and then run parallel to the East Coast.

They temporarily downgraded Earl to a category three storm on Wednesday, but the hurricane strengthened to a category four again later in the day.

“The most important thing for people living in Earl’s potential tract to do is to listen to and follow the instructions of their local officials,” Fema administrator Craig Fugate said.

A hurricane warning has been issued for the east coast of the US from Bogue Inlet, North Carolina north-eastward to the North Carolina/Virginia border, including the Pamlico and Albemarle sounds.

The hurricane watch has been adjusted northward and now extends from the North Carolina/Virginia border northward to Massachusetts, including Martha’s Vineyard and Nantucket.

A warning means hurricane conditions are expected somewhere within the affected area, with the first tropical storm-force winds within 36 hours. A watch expects the same within 48 hours.

The local authorities in the Outer Banks expect the storm to pass 80 miles (130km) away from the islands, meaning high winds and waves are likely.

The hurricane is currently east of the central Bahamas and is moving north-west.

On Monday the hurricane battered north-eastern Caribbean islands and Puerto Rico, causing power cuts and flooding.

Earl is being followed by Tropical Storm Fiona, currently moving north of the Leeward Isles, and Tropical Storm Gaston, the fourth tropical storm to have formed in the last 11 days.

http://www.bbc.co.uk/news/world-us-canada-11154296

The current Geostationary Operational Environmental Satellite GOES-13 captured this image of Hurricane Danielle heading for the north Atlantic (top center), Hurricane Earl with a visible eye hitting the Leeward Islands (left bottom) and a developing tropical depression 8 (lower right) at 1:45 p.m. EDT on Aug. 30. Image Credit: NASA/NOAA GOES Project

A MEMBER of Avon Glen Pipes and Drums was injured in a freak accident at Whitchurch Village Fete.

A MEMBER of Avon Glen Pipes and Drums was injured in a freak accident at Whitchurch Village Fete.

A gust of wind lifted two gazebos from their moorings and they flew through the air towards the band who were playing in the arena.

One of the gazebos knocked Pipe Major Bill Plenty, 81, to the ground.

The former fireman limped from the field, and Mr Plenty, of Whitchurch, who has been in the band for 50 years, said: “The wind caught the gazebo and it took off and decided to clump me.

“I saw it coming towards us and I turned to yell a warning to the band and it hit me.”

He suffered bruising to one of his legs.

It was not the only incident to mar an otherwise successful event, as vandals struck at the flower tent on Wednesday night, causing nearly £1,000 worth of damage.

The fete committee then had to fork out £150 for fencing around the field to prevent any further problems.

The same night, vandals damaged fencing at Whitchurch allotments and superglued the locks at the church hall.

Committee member Peter Edwards said: “The money that we will have to spend to replace the panels in the hired tent comes out of the money that we give out every November to deserving causes and groups in the Whitchurch area – it’s so frustrating.

“It is fortunate that Michael Eavis, who runs the Glastonbury Festival, and Bristol International Airport gave us £500 in sponsorship. If it hadn’t been for them we would have been in trouble.”

Around 3,000 people attended the fete, launched by villager Ashton Broad.

His daughters Sam Parsons and Kimberley Broad are on the flower show committee and his son Oliver also helps out.

The horse show made a welcome return this year and there was also a dog show, birds of prey, a climbing wall and alpacas.

John Silverthorne won the cup for the best overall horticultural exhibit for his tomatoes and he also won first prizes for the largest marrow, best potatoes and single rose. Marcia Devonald won first prize for runner beans.

Libby Brown won the Bert Keep Cup for the best overall children’s exhibit for her painting of a tree.

Whitchurch Village Fete Princess was Emily Payne, 10, and her attendants were Ellie Marshall, nine and Ella-Mae Parsons, eight.

http://www.thisisbristol.co.uk/news/Flying-gazebo-hits-Pipe-Major-81/article-2586780-detail/article.html

A storm moving through the eastern Caribbean has strengthened to a Category Four hurricane, prompting warnings for several islands.

Hurricane Earl is expected to gain more strength before heading towards the US.

Forecasters say it is a major hurricane and could cause “catastrophic” damage if it hits land.

Strong winds and heavy rains are already lashing several islands in Caribbean, but the storm has now passed by the Virgin Islands.

The hurricane is generating sustained winds of 215km/h (135mph).

It is currently north-east of Puerto Rico, and moving west-northwest at about 24km/h, the US-based National Hurricane Center (NHC) reports.

The centre of the storm is expected to move away from the Virgin Islands on Monday night and pass to the east of the Turks and Caicos on Tuesday night.

Hurricane warnings in place on several islands in the region have now been degraded.

However, Earl caused heavy rains and flooding in low-lying areas, and it damaged homes on several islands including Antigua and Barbuda.

Several countries reported power outages. Cruise ships were diverted and flights cancelled across the region.

The NHC said it was too early to say what effect Earl would have on the eastern US coast later in the week, but it warned coastal residents from North Carolina to Maine to watch the storm’s path.

Earl is being closely followed by Tropical Storm Fiona, currently east of the Leeward Isles with winds of up to 65km/h.

http://www.bbc.co.uk/news/world-latin-america-11128738

The tree uprooted by the twister narrowly missed taking down a power line

High winds described as a small “twister” hit a Norfolk town, causing minor damage to homes, power lines to swing violently and trees to fall.

The winds, which hit Watton on Sunday afternoon, uprooted an oak tree and residents reported damage to tiled roofs and school playgrounds.

Branches were thrown across roads but no major problems have been reported.

Weather experts said it was possible the damage had been caused by a funnel cloud or “twister”.

Resident Stevie Willis said: “Tiles came off roofs and the local primary school’s outside adventure play area received some damage.

“A few family back gardens were also hit.

“My sister and niece stood at the front door and watched it go through.”

A spokesman for BBC forecaster Weatherquest said: “About that time, a line of thunderstorms came through from the North Sea, and Watton was in line with them.

“It is likely to be a funnel cloud or a twister would form and because there was damage on the ground it is likely to be the case.”

http://www.bbc.co.uk/news/uk-england-norfolk-11126311